Ch 3 Ex 11 Flashcards
The plasma membrane acts as a protective barrier for the cell.
The plasma membrane surrounds the internal structures of the cell, forming a flexible barrier between the intracellular and extracellular environments. It separates the cell contents from the surrounding environment.
The lysosomes are often called “suicide sacs.”
The lysosomes are often called “suicide sacs” because of their potential ability to digest and therefore destroy the entire cell.
The first, primitive, cells are called prokaryotes.
According to current scientific understanding, the first, primitive cells are called prokaryotes. They are considered the earliest form of life on Earth and include organisms like bacteria and archaea.
The size of most animal cells is restricted to a range of 10 to 30 micrometers in diameter.
Most animal cells typically range in size from 10 to 30 micrometers in diameter. The primary reason for this size restriction is the cell’s surface area to volume ratio. A smaller cell has a larger relative surface area, allowing for more efficient transport of nutrients and waste products.
Cardiac and skeletal muscle tissue have two or more nuclei.
While skeletal muscle tissue typically has multiple nuclei per cell, cardiac muscle cells usually only have one nucleus per cell, meaning they do not have two or more nuclei like skeletal muscle cell do.
*Skeletal muscle: multinucleated, meaning each cell contains multiple nuclei.
*Cardiac muscle: usually only one nucleus per cell, sometimes with a very small number having two nuclei.
The AFM (atomic force microscope) has led to a greater understanding of the causes of some diseases that have devastated both humans and animals.
An AFM allows scientists to study the surface structures of materials at the nanoscale, which has been crucial in understanding the mechanical properties of cells and tissues, leading to insights into the mechanisms behind various diseases affecting both humans and animals, including cancer, viral infections, and neurodegenerative disorders.
Prions can generate grossly visible holes in the brain tissue.
While prions do cause significant damage to brain tissue, they typically do not create holes that are visible to the naked eye; instead, the characteristic damage from prions appears as microscopic “holes” or vacuoles that give the brain a sponge-like appearance when viewed under a microscope, hence the term “transmissible spongiform encephalopathy” used to describe prion diseases.
The cell membrane is not visible using light microscopy.
A cell membrane is typically not visible under a light microscope because its thickness is too small to be resolved by the microscope’s resolution limitations.
Insulin stimulates glucose uptake.
Yes, insulin stimulates glucose uptake into cells by moving glucose transporter 4 (GLU 4) proteins from storage vesicles to the plasma membrane. This process allows glucose to enter the cell and be used for energy or stored.
Flagella and cilia, extensions of the plasma membrane, are structurally identical but function differently.
While flagella and cilia share a similar internal structure (both composed of microtubules arranged in a “9+2” pattern), they differ primarily in their length, number per cell,, and the way they move, leading to distinct functions within the cell.
*Flagella are typically longer and whip-like, while cilia are shorter and hair-like.
*A cell usually has only one or a few flagella, whereas cilia are present in large numbers on the cell surface.
*Flagella move in a wave-like motion to propel the entire cell, while cilia often beat in coordinated waves to move substances along the cell surface.
Mitochondria are known as the powerhouses of the cell.
Cells can have as few as 100 mitochondria or as many as several thousand. The mitochondria can self-replicate when increased energy demands are placed on the cell. Energy is stored in the phosphate bonds of adenosine triphosphate (ATP).
Animals, even inactive ones, must consume water or they will die in a relatively short time.
Even animals that appear inactive, like those in hibernation or estivation, still require some water intake to survive, and without it, they will eventually die within a relatively short time frame due to dehydration.
The fluid of the cell is called cytosol and has a thick jelly-like consistency.
The fluid inside a cell is called cytosol and it does indeed have a thick, jelly-like consistency due to the presence of various dissolved molecules and proteins suspended in water.
Crystalloids are good for rehydrating extravascular spaces.
Crystalloids solutions are considered good for rehydrating extravascular spaces because they readily distribute fluid throughout the body, including the interstitial fluid, which is the fluid surrounding cells within the extravascular space, due to their small molecule size that easily passes through capillary walls.
Colloids are good for raising blood pressure.
Colloids raise blood pressure because they increase the “colloid osmotic pressure” within the blood vessels, essentially pulling fluid back into the circulatory system from the surrounding tissues, thereby expanding the blood volume and consequently increasing blood pressure; this effect is primarily due to the large molecules present in colloids, like albumin, which are unable to easily pass through capillary walls. Found in blood plasma.
